Question

对于我的地图应用程序，我想在不同的函数中使用ol.View.zoom-property以及ol.View.resolution属性。根据Open Layers 4 API文档，如果给出了解决方案，则会忽略zoom属性。因此，我正在尝试应用getZoomForResolution，这将在API中记录：

https://openlayers.org/en/latest/apidoc/ol.View.html#getZoomForResolution

这是我使用的一些测试代码：

var map, view;
    //initial definition of the map
    function initializeMap(){
        //define osm source and layer
        var osmSource = new ol.source.OSM();
        var osmLayer = new ol.layer.Tile({source: osmSource});
        //define new map object
        map = new ol.Map({
            target:'map',
            view: new ol.View({
                center: ol.proj.fromLonLat([9.83276, 52.36554]),
                resolution:300, // is required in some function
                zoom:10 //ignored as expected according to API, also required in another function
            }),
            layers:[osmLayer]
        });
        var currentResolution = map.getView().getResolution(); // returns 300 as expected
        console.log(map.getView().getZoomForResolution(currentResolution));
    }

不幸的是，我只收到错误“map.getView（）。getZoomForResolution不是函数”。我也读过this帖子，但是它指的是OL 3，没有给出证据。

所以，我的问题是：getZoomForResolution函数是不是已经实现了？或者我试图访问它的方式是否有错误？

Answer 1

在这里工作得很好。 https://codepen.io/anon/pen/vePjxa?editors=1011

 var osmSource = new ol.source.OSM();
    var osmLayer = new ol.layer.Tile({source: osmSource});
    //define new map object
    map = new ol.Map({
        target:'map',
        view: new ol.View({
            center: ol.proj.fromLonLat([9.83276, 52.36554]),
            resolution:300, // is required in some function
            zoom:10 //ignored as expected according to API, also required in another function
        }),
        layers:[osmLayer]
    });
    var currentResolution = map.getView().getResolution(); // returns 300 as expected
    console.log(map.getView().getZoomForResolution(currentResolution));

你有一个不起作用的沙箱吗？

是否在Open Layers 4中定义了getZoomForResolution？如果是这样，我如何让它工作？

1 个答案: